Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full behavioral burden and does so well: it discloses the data source, exact matching only, return contents on a hit, snapshot date, no API key/account requirement, and per-call cost with x402 payment.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the usage condition and contains no filler. Each sentence adds actionable information about scope, matching behavior, return values, cost, or authentication.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple one-parameter check with no output schema or annotations, the description is complete enough: it explains what is checked, what a hit returns, matching strictness, snapshot date, access requirements, and pricing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The single address parameter is already fully documented in the schema. The description adds useful context by stating the 16-currency scope and exact matching behavior, though it does not need to do much more for a one-parameter tool.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description gives a specific verb and resource: it checks a crypto address against the OFAC SDN list. It also explicitly distinguishes the result from a risk score, which helps separate it from sibling tools such as evm_verdict or evm_token_safety.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It clearly states the usage condition: use when deciding whether an agent may transact with an address at all. It also implies when not to use it by saying it is not a risk score, but it does not explicitly name alternative tools for risk scoring.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.